STORAGE AND DISTRIBUTION. 



be drawn. One or two feet difference in level will 

 suffice to lift the water 

 over the bank, whence 

 it flows by gravity to 

 the point at which it 

 is required. The idea 

 is show by fig. 85, in 

 which the pipe is laid 

 along the inner slope 

 and above the puddle 

 wall and to a valve 

 well at the foot of the 

 outer slope, in which 

 is placed a regulating 

 valve and a scour 

 valve. The only other 

 necessary adjunct is 

 a small hand air- 

 pump, which is placed 

 in a house erected on 

 the top of the bank. 

 This form of con- 

 struction is greatly to 

 be advised wherever 

 water has to be drawn 

 from such a reservoir, 

 whether for direct 

 supplies or for driving 

 turbines or hydraulic 

 rams. The purest 

 water is drawn about 

 J the way down from 

 top water level, but 

 valves may be placed at any desired level actuated 



